Micromirror devices are micro-machined micro-electro-mechanical systems (MEMS), also known as micro-opto-electro-mechanical system (MOEMS). A typical micromirror device, or digital micromirror device (DMD) is comprises several hundred thousand mirrors, each approximately 16 μm square on a 17 μm grid. Each mirror is selectively able to rotate approximately 10 degrees in either a positive or negative direction about a torsion hinge.
DMDs are widely used in display applications. In display applications, each mirror is used to control light destined for one pixel of a projected image. Since DMDs typically operate in either a full-on state, in which incident light is directed towards a display screen, or in a full-off state, in which incident light is directed away from the display screen, pulse width modulation is necessary to create gray scale images.
While DMDs have saturated the display market, they have not made inroads into non-display markets such as optical communication. Since a large number of mirrors typically is not necessary in optical communication markets, MEMS devices used in optical communications typically use a single relatively large mirror. Inefficiencies have thus far prevented DMDs from gaining acceptance in the optical communications markets. What is needed is a DMD design and method of operation that improves efficiency of the micromirror array in optical communications markets.